1. Field of the Invention
This invention relates to a thermoelectric element device that directly converts thermal energy to electric energy, or electric energy to thermal energy, and a thermoelectric module composed of such a thermoelectric element device.
2. Description of the Related Art
Generally, a thermoelectric element device is composed of two electrodes opposing each other and a pair of a p-type thermoelectric transducer semiconductor and an n-type thermoelectric transducer semiconductor that are interposed between the two electrodes. In such a device, thermoelectric effect such as the Thomson effect, the Peltier effect and the Seebeck effect is utilized to directly transduce thermal energy to electric energy and conversely. Practically, a thermoelectric module is used which is composed by arranging the thermoelectric element device in parallel.
An example of such a thermoelectric element device or a thermoelectric module is disclosed in Japanese Patent Application Laid-open Publication No. 2005-64457. This publication discloses a thermoelectric transducer apparatus composed of opposingly disposed electrodes, p-type thermoelectric direct transducer semiconductors and n-type thermoelectric direct transducer semiconductors. The semiconductors each are column-shaped and stand together in large numbers between the two electrodes. The semiconductors are soldered to a heat radiation electrode that has in part an elastic meshwork member that abuts the semiconductors slidably.
In the related-art thermoelectric transducer apparatus, since the meshwork member can deform and slide with regard to the semiconductors, a thermal stress due to the difference in coefficient of thermal expansions between a heat-absorbing electrode and the thermoelectric semiconductors is alleviated, thereby avoiding breakage or damage of the thermoelectric transducer apparatus, according to the above publication.
However, since a contact area between the meshwork member and the thermoelectric semiconductor (thermoelectric element) is small, heat may not be evenly distributed in the contact area, which leads to a disadvantage that the thermoelectric transducer apparatus cannot demonstrate an efficiency of thermoelectric conversion up to its inherent capability.
In addition, a corrective measure has not been taken which facilitates to spread the thermal energy from the meshwork member across the surface of the contact area between the thermoelectric semiconductor and the meshwork member. This causes another disadvantage that electromotive force generated in the thermoelectric element cannot be fully utilized when transducing the thermal energy to electric energy.
The present invention has been made in order to eliminate the above disadvantages and the objective thereof lies in a provision of a thermoelectric element device which alleviates a thermal stress in the thermoelectric element device and evenly distributes heat on the surface of the thermoelectric element, the surface meeting the electrode thereof, thereby improving a performance and thermoelectric conversion efficiency of the thermoelectric element device, and a thermoelectric module employing such a thermoelectric element device.
A first aspect of the present invention provides a thermoelectric element device comprising a first electrode including an electrode member, an elastic member being electrically conductive and being provided on the electrode member, and a heat uniforming member being electrically conductive and being provided on the elastic member; a thermoelectric element being made of a material having thermoelectric effect and being arranged on the first electrode so as to contact the heat uniforming member; and a second electrode being arranged on the thermoelectric element.
In addition, it is preferable in the thermoelectric element that the second electrode includes an electrode member, an elastic member being electrically conductive and being provided on the electrode member, and a heat uniforming member being electrically conductive and being provided on the elastic member; and that the thermoelectric element is arranged on the second electrode so as to contact the heat uniforming member.
Moreover, elasticity of the elastic member is preferably larger than the elasticity of the thermoelectric element and is equal to or larger than the elasticity of the first electrode in the above thermoelectric element. Furthermore, the heat uniforming member has preferably a thermal conductivity larger than that of the thermoelectric element.
The heat uniforming member has preferably a thermal conductivity larger than that of the thermoelectric element.
The heat uniforming member is preferably made of any chemical element of iron, nickel, tantalum, titanium, tungsten, copper, and carbon; a substance containing any one of the chemical elements as a primary constituent; an alloy, compound, or mixture of two or more of the chemical elements and the substances; and a member obtained by joining two or more of the chemical elements, the substance, the alloy, the compound, and the mixture.
More preferably, the thermoelectric element comprises a pair of thermoelectric elements including an n-type conduction portion and a p-type conduction portion that are separated apart from each other; and either one of the first electrode and the second electrode includes a first portion arranged on the n-type conduction portion and a second portion arranged on the p-type conduction portion, the first and second portion being separated apart from each other.
A second aspect of the present invention provides a thermoelectric module comprising a plurality of thermoelectric element devices that each are arranged so as to be electrically connected to an adjoining thermoelectric element device. Each of the thermoelectric element devices is any one of the aforementioned ones.
According to the present invention applied to the thermoelectric element device and the thermoelectric module employing the same, there can be alleviated a thermal stress caused in the thermoelectric element device by the elastic member; and there can be evenly distributed an in-plane temperature of the thermoelectric element since the thermoelectric element is provided with the heat uniforming member configured to evenly distribute the thermal energy incoming from the elastic member two-dimensionally in the thermoelectric member, thereby improving the thermoelectric conversion efficiency of the thermoelectric element device and the thermoelectric module employing the same.